1. Field of the Invention
The present invention relates to a unit interconnection substrate and an interconnection substrate for forming a mount structure of electronic parts or an electronic device obtained by mounting a plurality of leadless type semiconductor chips or other electronic parts superposed on each other in two or more stages on a mount substrate, a mount structure of electronic parts and an electronic device formed by using those, a method for mounting electronic parts for forming the mount structure of the electronic parts and a method for manufacturing an electronic device for forming such an electronic device.
2. Description of the Related Art
Conventionally, a mount structure of electronic parts or an electronic device as shown in FIG. 13 has been known.
In this mount structure of electronic parts or electronic device, two or more thin small outline package (TSOP) type semiconductor chips or other electronic parts 60 are superposed on each other on a mount substrate 80. Then, each of the leads 64 extended to the plurality of semiconductor chips or other electronic parts 60 is superposed on each other on conductor pads 92 provided on a top surface of the mount substrate 80 corresponding to those and electrically connected by soldering or the like.
Summarizing the problem to be solved by the invention, recently, for the purpose for improving the electrical characteristics of the semiconductor chips or other electronic parts and the purpose of reducing the mount area of the electronic parts, types have appeared for electrically connecting a semiconductor chip directly to the conductor pads of the mount substrate by a flip chip bonding and surface mounting the semiconductor chip on the mount substrate or types have appeared for electrically connecting a chip size package (CSP) type semiconductor device to the conductor pads of the mount substrate and surface mounting the semiconductor device on the mount substrate. These are employed in many electronic apparatuses.
In a semiconductor chip or semiconductor substrate of the type to be surface mounted on this mount substrate, the leads are not extended, so it is impossible to mount two or more leadless type semiconductor chips or semiconductor devices or other electronic parts superposed on the mount substrate.
An object of the present invention is to provide a unit interconnection substrate and an interconnection substrate for mounting a plurality of leadless type electronic parts as described above superposed in two or more stages on a mount structure, a mount structure of electronic parts and an electronic device formed by using the same, a method for mounting electronic parts for forming the mount structure of the electronic parts, and a method for manufacturing an electronic device for forming an electronic device.
To attain the above object, according to a first aspect of the present invention, there is provided a unit interconnection substrate comprised of an insulating substrate, an interconnection circuit provided with connection terminals and conductor pads provided on a top surface of the insulating substrate, a depression for holding an electronic part formed in a bottom surface of the insulating substrate, and connection terminals provided on the bottom surface of the insulating substrate on the periphery of the depression, the connection terminals being electrically connected to the connection terminals provided on the interconnection circuit via conductor through holes or conductor via holes provided in the insulating substrate.
Preferably, a plurality of unit interconnection substrates of the present invention are integrally formed arranged in many columns or one column.
According to a second aspect of the present invention, there is provided a first mount structure of electronic parts wherein an electronic part is electrically connected to conductor pads provided on interconnection circuits of the top surface of a unit interconnection substrate or other interconnection substrate, the electronic part is mounted on the unit interconnection substrate or interconnection substrate, the connection terminals of the bottom surface of the unit interconnection substrate or the interconnection substrate are electrically connected to the corresponding connection pads of the mount substrate, and, at the same time, the electronic part mounted on the mount substrate is held in a depression in the bottom surface of the unit interconnection substrate or interconnection substrate.
According to a third aspect of the present invention, there is provided a second mount structure of electronic parts wherein an electronic part is electrically connected to conductor pads provided on an interconnection circuit of a top surface of an unit interconnection substrate or interconnection substrate, a plurality of the unit interconnection substrates or interconnection substrates with electronic parts mounted thereon are superposed in two or more stages on each other, the connection terminals of vertically superposed unit interconnection substrates or interconnection substrates are electrically connected to each other, an electronic part mounted on a lower unit interconnection substrate or interconnection substrate is held in a depression of the bottom surface of an upper unit interconnection substrate or interconnection substrate, connection terminals of the bottom surface of the lowermost unit interconnection substrate or interconnection substrate among the two or more stages of superposed unit interconnection substrates or interconnection substrates are electrically connected to corresponding connection pads of the mount substrate, and an electronic part mounted on a mount substrate is held in the depression of the bottom surface of the lowermost unit interconnection substrate or interconnection substrate.
According to a fifth aspect of the present invention, there is provided a first electronic device comprising the first mount structure of electronic parts in which, in place of the mount substrate, use is made of a unit interposer or an interposer provided on its top surface with conductor pads for connecting an electronic part and connection pads for connecting connection terminals provided on the bottom surface of the unit interconnection substrate or interconnection substrate and provided on its bottom surface with connection pads for connecting an external electronic circuit electrically connected to the connection pads of the top surface.
According to a sixth aspect of the present invention, there is provided a second electronic device comprising the second mount structure of electronic parts in which, in place of the mount substrate, use is made of a unit interposer or an interposer provided on its top surface with conductor pads for connecting electronic parts and connection pads for connecting connection terminals provided on the bottom surface of the unit interconnection substrate or interconnection substrate and provided on its bottom surface with connection pads for connecting an external electronic circuit electrically connected to the connection pads of the top surface.
According to the first or second mount structure of electronic parts of the present invention or the first or second electronic devices of the present invention, leadless type semiconductor chips or other electronic parts can be mounted via the unit interconnection substrate or the interconnection substrate of the present invention on the mount substrate, the unit interposer, or the interposer superposed on each other in two more stages or leadless type semiconductor chips or other electronic parts can be mounted via the unit interconnection substrate or the interconnection substrate of the present invention on the mount substrate, the unit interposer, or the interposer superposed on each other in three or more stages.
Further, other electronic parts other than the electronic part mounted on the uppermost unit interconnection substrate or the uppermost interconnection substrate can be held in the depressions of the bottom surfaces of the unit interconnection substrates or the interconnection substrates and the electronic parts can be protected by covering the same by the insulating substrates of the unit interconnection substrates or the interconnection substrates so as not to be subjected to external force.
Further, in the first or second electronic device of the present invention, the connection pads provided on the bottom surface of the unit interposer or the interposer can be electrically connected to the corresponding connection pads etc. provided on the mount substrate to mount the first or second electronic device on the mount substrate etc.
In the unit interconnection substrate of the present invention, preferably the depression is a through groove extending from one side face of the insulating substrate to a side face on the opposite side.
In the interconnection substrate of the present invention, preferably the depression is a through groove extending from one side face of the insulating substrate to a side face on the opposite side and formed in a direction perpendicular to a direction wherein the plurality of unit interconnection substrates are arranged in many columns or one column.
In this unit interconnection substrate or interconnection substrate, heat generated by the electronic parts such as the semiconductor chip held in the depression can be efficiently dissipated into the atmosphere on the outside of the insulating substrate through the through groove.
Further, in comparison with a hollow like depression with the periphery surrounded by the insulating substrate, the depression formed by the through groove can be easily and quickly formed in the bottom surface of the insulating substrate by using a router or the like without trouble.
According to seventh aspect of the present invention, there is provided a first method for mounting electronic parts comprising the steps of:
a. electrically connecting electronic parts to conductor pads provided on interconnection circuits of top surfaces of unit interconnection substrates of an interconnection substrate of the present invention and mounting the electronic parts on said interconnection substrate,
b. cutting the interconnection substrate between predetermined unit interconnection substrates thereof with said electronic parts mounted thereon to form an interconnection substrates each having a predetermined number of unit interconnection substrates with the electronic parts mounted thereon, and
c. electrically connecting the connection terminals provided on a bottom surface of the interconnection substrate having a predetermined number of the unit interconnection substrates with said electronic parts mounted thereon to the corresponding connection pads of the mount substrate and holding the electronic parts mounted on the mount substrate in the depressions of the bottom surface of said interconnection substrate.
In this first mount method of electronic parts, the first mount structure of the electronic parts of the present invention formed by mounting a plurality of electronic parts on the mount substrate superposed on each other in two stages and laterally arranged can be easily formed without trouble.
According to an eighth aspect of the present invention, there is provided a second method for mounting electronic parts comprising the steps of:
a. forming at least two structures each obtained by electrically connecting electronic parts to conductor pads provided on interconnection circuits of top surfaces of unit interconnection substrates of an interconnection substrate and mounting the electronic parts on said interconnection substrate,
b. superposing the interconnection substrates with the electronic parts mounted thereon superposed on each other in two or more stages and electrically connecting the connection terminals of upper and lower superposed interconnection substrates each other and, at the same time, holding the electronic parts mounted on the lower interconnection substrates in the depressions of the bottom surface of the upper interconnection substrate,
c. vertically cutting said interconnection substrates superposed on each other in two or more stages between predetermined unit interconnection substrates thereof to form interconnection substrates each having the predetermined number of the unit interconnection substrates with the electronic parts mounted thereon superposed on each other in two or more stages, and
d. electrically connecting the connection terminals provided on the bottom surface of the lowermost interconnection substrate among the interconnection substrates each having the predetermined number of the unit interconnection substrates superposed on each other in two or more stages to the corresponding connection pads of the mount substrate and, at the same time, holding the electronic parts mounted on the mount substrate in the depressions of the bottom surface of said lowermost interconnection substrate.
In this second mount method of the electronic parts, the second mount structure of the electronic parts of the present invention formed by mounting a plurality of electronic parts on the mount substrate via the interconnection substrate having the predetermined number of the unit interconnection substrates superposed on each other in three or more stages and arranged in a lateral direction or the like can be easily formed without trouble.
A method of manufacture of the first electronic device of the present invention comprises the steps of:
a. electrically connecting electronic parts to conductor pads provided on interconnection circuits of top surfaces of unit interconnection substrates of the interconnection substrate of the present invention and mounting the electronic parts on said interconnection substrate,
b. electrically connecting the connection terminals provided on the bottom surface of said interconnection substrate to the connection pads of the top surface of an interposer and holding the electronic parts mounted on the interposer in the depressions of the bottom surface of said interconnection substrate electrically connected to the conductor pads of the top surface of said interposer, and
c. vertically cutting the interconnection substrate with said electronic parts mounted thereon and unit interposers beneath the same, between predetermined unit interconnection substrates of the interconnection substrate.
In this method of manufacture of the first electronic device, the first electronic device formed by mounting a plurality of electronic parts on the unit interposer or the interposer via the interconnection substrate having the predetermined number of unit interconnection substrates superposed on each other in two stages and arranged laterally or the like can be easily formed without trouble.
Further, the method of manufacture of the second electronic device of the present invention comprises the steps of:
a. forming at least two structures each obtained by electrically connecting electronic parts to conductor pads provided on interconnection circuits of top surfaces of unit interconnection substrates of an interconnection substrate and mounting the electronic parts on said interconnection substrate,
b. superposing the interconnection substrates with the electronic parts mounted thereon on each other in two or more stages and electrically connecting the connection terminals of the upper and lower superposed interconnection substrates superposed to each other and, at the same time, holding the electronic parts mounted on a lower interconnection substrate in the depressions of the bottom surface of an upper interconnection substrate,
c. electrically connecting the connection terminals provided on the bottom surface of the lowermost interconnection substrate of said interconnection substrates superposed on each other in two or more stages to the connection pads of the top surface of an interposer and, at the same time, holding the electronic parts mounted on the interposer connected to the conductor pads of the top surface of said interposer in the depressions of the bottom surface of said lowermost interconnection substrate, and
d. vertically cutting said interconnection substrates superposed on each other in two or more stages and the unit interposers beneath the same, between predetermined unit interconnection substrates of the interconnection substrate.
In this method of manufacture of the second electronic device, the second electronic device of the present invention formed by mounting a plurality of electronic parts on a unit interposer or interposer via the interconnection substrate having the predetermined number of the unit interconnection substrates superposed on each other in three or more stages and arranged laterally or the like can be easily formed without trouble.